#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define rep(i, a, b) for (int i = (a); i <= (b); i++)
#define per(i, a, b) for (int i = (a); i >= (b); i--)
#define endl '\n'
const int N = 1005;

int n, m;
pii a[N];
pii b[N];
bool equal() {
  rep(i, 1, n) if (a[i] != b[i]) return false;
  return true;
}
void solve() {
  cin >> n;
  rep(i, 1, n) cin >> a[i].first >> a[i].second;
  sort(a + 1, a + n + 1);
  int x2 = a[1].first + a[n].first;
  rep(i, 1, n) b[i] = pii(x2 - a[i].first, a[i].second);
  sort(b + 1, b + n + 1);
  if (equal())
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}